The proposed study is a randomized controlled trial (RCT) that will rigorously evaluate the effectiveness and cost-effectiveness of delivering a multimedia evidence-based intervention (WORTH) and streamlined HIV testing to prevent HIV and other sexually transmitted infections (STIs) with Black/African-American (hereafter referred to as Black) women drug users in probation sites in New York City (NYC), compared to streamlined HIV testing alone. The primary outcome will be to reduce cumulative incidence of biologically confirmed STIs (i.e., Chlamydia, gonorrhea and trichomonas). Advancing a continuum of HIV interventions in probation settings nationwide has tremendous potential for reaching a large number of drug-involved Black women who remain at very high risk for HIV/STIs and helping to reverse highly concentrated HIV/STI epidemics in their networks and communities. The proposed RCT will be conducted with 420 drug-involved Black women at 5 probation sites located in communities in NYC heavily affected by HIV and STIs. Eligible women will be randomly assigned to: (1) WORTH consisting of an individual Streamlined HIV Testing session followed by a 4-session group-based multimedia HIV/STI prevention intervention or (2) an individual Streamlined HIV Testing session alone, which will serve as the comparison condition. Both conditions will be delivered by probation providers at the 5 probation sites. Repeated assessments will occur at baseline and 3, 6, and 12- months post intervention. This study will also employ mixed methods to identify multi-level theory-driven factors that may influence the effectiveness of delivering WORTH and Streamlined HIV testing interventions in the real world setting of probation to inform future dissemination strategies for these interventions. We will conduct repeated assessments and qualitative interviews on multi-level factors that may influence the effectiveness of WORTH on study outcomes with probation providers delivering the interventions, frontline probation staff, and probation administrators. If the multimedia WORTH intervention is found to be effective, it may be scaled up in probation settings nationwide to curb the spread of HIV/STIs among Black women and to reduce HIV disparities in heavily impacted communities. If no difference is found between study arms, the Streamlined HIV Testing intervention offers a highly cost-efficient model of HIV testing that may also be scaled up in probation settings.